This invention relates to a hot water floor heating system for use in connection with a movable structure exposed to cold weather. More particularly, the invention is directed to a gravity-operated hot water circulation heating system for use in outdoor storage cabinets, hunting blinds, ice shanties and the like.
Hot water heating systems have long been used to heat structures during periods of cold weather. Such systems generally include a heating element, a water reservoir exposed to the heating element, a pump and a piping or conduit system which extends through the structure for circulating hot water from the reservoir through the structure and back to the reservoir. Systems of this type generally include a radiator or the like located within each space of the structure to be heated. All of the components of the system are permanently mounted within the structure and require a significant amount of time and effort to install.
In non-permanent or movable structures, it is known to provide a space heater for heating the interior of the structure. This type of heating arrangement is common in movable structures such as hunting blinds or ice fishing shacks. Heaters of this type take up space within the interior of the structure and provide uneven heat, in that the amount of heat provided to areas remote from the heater is less than that provided to areas closer to the heater. Further, this type of heating arrangement provides little heat to the lower area of the interior adjacent the floor, since heat discharged from the heater tends to rise. Structures of the this type are typically used in cold weather, and it is thus common for occupants to experience uncomfortably cold feet.
The same general difficulties are encountered in movable structures which are not intended for occupation by humans, such as cabinets which are located at a construction site or on a vehicle for storing supplies which require heat. Depending on the nature of the items contained within the structure, it may not be possible to locate a heater within the interior of the structure. For example, some types of heaters cannot be located within the interior of a structure housing petroleum products, due to the flammability of such products.
Further, when a gas-fired heater is used, it is necessary to vent the heater to the outside of the structure in order to prevent buildup of combustion fumes in the interior of the structure.
It is an object of the present invention to provide a heating system for a movable structure in which the heating element is located outside the interior of the structure, so as to eliminate the need to vent the heater and to make available the interior space which otherwise would be occupied by the heating element and its associated venting. A further object of the invention is to provide such a system which distributes heat evenly throughout the interior of the structure. Yet another object of the invention is to provide such a system in which heat is supplied to the lower areas of the structure adjacent the floor. A still further object of the invention is to provide such a system which is relatively simple in its components and construction, yet which provides highly satisfactory heat distribution and operation.
In accordance the present invention, a structure includes one or more walls and a floor which cooperates to define an interior, and a heating arrangement is associated with the floor. The heating arrangement includes an internal cavity which underlies the floor and which contains a quantity of fluid, and a heater located exteriorly of the structure. A circulating arrangement is interconnected between the internal cavity and the heating arrangement for circulating fluid from the heater to the internal cavity and from the internal cavity to the heater. The circulating arrangement is preferably in the form of a fluid inlet associated with the internal cavity for receiving heated fluid from the heater, and a fluid outlet associated with the internal cavity for supplying return fluid to the heater from the internal cavity. Heated fluid from the inlet circulates through the internal cavity toward the outlet, and heat from the fluid is dissipated through the floor for heating the interior of the structure. The internal cavity may be defined by a substantially flat tank underlying the floor, and the tank may be constructed and configured so as to underlie substantially the entire surface area of the floor. The tank preferably includes an upper wall over which the floor is located, and one or more side walls depending from the upper wall. The fluid inlet and the fluid outlet are preferably interconnected with one of the tank side walls. The tank is preferably oriented at an angle to horizontal such that the fluid inlet is located at an elevation above that of the fluid outlet, to enable fluid to flow by gravity from the inlet to the outlet. The heater is preferably in the form of a gravity-type heater interconnected with the fluid outlet for receiving return fluid therefrom and interconnected with the fluid inlet for supplying heated fluid thereto. A removable and replaceable fuel tank is adapted for interconnection with the heater, and may either be located within the interior of the structure or exteriorly of the structure. An insulating layer preferably underlies the tank for preventing heat from dissipating from the tank other than through the floor. The structure may either be adapted for storage of items or for occupation by humans, such as a hunting blind or an ice fishing shack.
In accordance with another aspect of the invention, a heated floor arrangement adapted for use with a structure includes a heater having an inlet port and an outlet port, and a container or tank including a heat-conductive floor having an upper surface spaced from a lower surface. An inlet valve and an outlet valve are connected to the container and communicate with the space between the upper and lower surfaces of the heat-conductive floor. Tubing is interconnected between the outlet valve and the inlet port of the heater and between the inlet valve and the outlet port of the heater, for circulating fluid to the container from the heater and from the container to the heater. The heat-conductive floor defines a point of lowermost elevation located adjacent the outlet valve, and the inlet valve is positioned at an elevation above that of the outlet valve. The heat-conductive floor slants downwardly from the location of the inlet valve toward the location of the outlet valve, for circulating fluid by gravity through the container. The heat-conductive floor preferably slopes downwardly in both a first direction from the inlet valve toward the outlet valve, and in a second direction transverse to the first direction toward the outlet valve, to ensure circulation of fluid to the outlet valve from the inlet valve.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.